Pandora-To-Vga Connection


skyeyemachine

Member
Joined
Dec 13, 2009
Messages
195
Hello all,

One of the few difficulties I'm anticipating with the Pandora is that I would have liked some means of easily connecting it to a computer monitor or the like. I know it has an S-video connection for use with televisions, but I was hoping there might be some relatively practical and inexpensive way to connect it to a VGA computer monitor I have kicking around, or possibly a DVI monitor in the future. The main reason I want to use the Pandora with an external monitor is so that I can do office-related stuff, like writing college essays or emails for example, on the device more comfortably when I'm around the house - and I'd rather not have to shell out for a new TV for the same purpose, seeing as I don't have one handy. Has anyone else been thinking about this? Any suggestions?

Also, I know that laptops and desktops and the like are more suited to these tasks, and that the Pandora was intended more as a gaming machine than a dedicated office assistant, but it would be convenient to have access to a larger display on the Pandora for working on documents (and gaming) as an alternative to loading up another computer and accessing the SD cards from that, as an alternative.

Finally, I've done a bit of looking, and all I'm really seeing are S-video-to-VGA converters, which tend to be in the $60-$90 range. Are there no useable alternatives to these devices? And I imagine there's no realistic way of modding such a feature into the Pandora using some of the hackable connections on the Pandora boards, right (something I probably wouldn't do even if I could, but it'd be nice to know if it's possible)?

Any constructive advice is much appreciated! :)
 
Even if you convert the S-Video signal to VGA, you'll only effectively be getting a PAL resolution (at best) which is 625 lines @ 50 Hz (roughly equivalent to 576i). The twist is that you get a vertical resolution of 576 scanlines @ 25 FPS and the horizontal resolution differs on each line, which makes it a horrible mess to convert to and from, giving you a horrible result if your goal is to read small text.
 
For the purposes you listed, using remote desktop software might be a better idea. Pandora sending and a PC receiving. Though USB -> VGA may allow a limited resolution (and limited spare Pandora power from driving it to use for applications)
 
zhasha said:
Even if you convert the S-Video signal to VGA, you'll only effectively be getting a PAL resolution (at best) which is 625 lines @ 50 Hz (roughly equivalent to 576i). The twist is that you get a vertical resolution of 576 scanlines @ 25 FPS and the horizontal resolution differs on each line, which makes it a horrible mess to convert to and from, giving you a horrible result if your goal is to read small text.

Mm, I've read some similar things that came up during my earlier searches. Is there no practical way to access the signals going to the Pandora's screen directly, then? Or am I stuck with the S-video only?

It's not a game-breaker if I can't do this, but it would have been a nice feature to have, although I guess a VGA or DVI connector would have bloated the Pandora boards and casing a bit, which is unfortunate. Perhaps someone will get one of those USB touchscreen extensions working with the Pandora eventually, and I can use those instead. <_<
 
Last edited by a moderator:
fischju2000 said:
For the purposes you listed, using remote desktop software might be a better idea. Pandora sending and a PC receiving. Though USB -> VGA may allow a limited resolution (and limited spare Pandora power from driving it to use for applications)

I considered remote desktop software before I decided to make this thread. It's really not worth bothering with in my case: I have a laptop with a built-in SD reader running Arch Linux, and it makes a lot more sense to just extract an SD card from the Pandora and pop it in that 98% of the time. What I was hoping was that I could exclude the second computer from my workflow altogether, and still have access to a larger screen when I'm staying put for a while.

As for USB-to-VGA, I hadn't considered that at all. I was aware of those USB monitors I mention above, but is there a USB-to-VGA adaptor for use with more common monitors? I'll have to look into that if so. I know I probably won't get a superb resolution, but I'm interested in seeing what I *can* get. :)
 
Last edited by a moderator:
skyeyemachine said:
fischju2000 said:
For the purposes you listed, using remote desktop software might be a better idea. Pandora sending and a PC receiving. Though USB -> VGA may allow a limited resolution (and limited spare Pandora power from driving it to use for applications)

I considered remote desktop software before I decided to make this thread. It's really not worth bothering with in my case: I have a laptop with a built-in SD reader running Arch Linux, and it makes a lot more sense to just extract an SD card from the Pandora and pop it in that 98% of the time. What I was hoping was that I could exclude the second computer from my workflow altogether, and still have access to a larger screen when I'm staying put for a while.

As for USB-to-VGA, I hadn't considered that at all. I was aware of those USB monitors I mention above, but is there a USB-to-VGA adaptor for use with more common monitors? I'll have to look into that if so. I know I probably won't get a superb resolution, but I'm interested in seeing what I *can* get. :)

http://www.nslu2-linux.org/wiki/HowTo/AddVGAAdapter
http://ubuntuforums.org/archive/index.php/t-260863.html

Some information. It will likely take a lot of power to drive these, we'd have to have a user test them. They aren't exactly cheap either, but much better picture quality than converting the composite. http://www.amazon.com/USB-2-0-VGA-Display-Adapter/dp/B000WTI6CI/ref=/ref=cm_cd_f_pb_i
 
Last edited by a moderator:
The only way I can think of without tremendous effort is to use a VGA Box. So any supporting Composite or S-Video would be fine.

I found this one that seems to be rated kinda OK ( 4 out of 5 stars on AMAZON after 21 reviews) , but then again for $30, I would only expect 1 star so maybe this is a good find?
 
@skyeyemachine
Tapping into LVDS is not exactly something you just do. The problem with what you're asking is basically that clasically, TVs were built with a better packing of round or otherwise non-square pixels, interleaved halfway between eachother. The image is then sent in 2 frames that update rows 1..3..5..n and 2..4..6..n-1 respectively (i.e. interlaced). If you take that signal and process it back to a matrix form, you need to somehow compensate or otherwise employ an algorithm to create a smoother image, but this ultimately kills small text and other things that rely on very few pixels. There's no good way (by using the video outputs on the console) to put your pandora screen up on a bigger one in decent enough resolution that it's actually an improvement. The S-Video out was obviously designed to fit old tube TVs and as such only push out what they can display.
 
http://global.kworld-global.com/main/index.aspx?flag=1

i still believe the only way to get a decent quality but you still wont be able to get more real resolution
 
zhasha said:
@skyeyemachine
Tapping into LVDS is not exactly something you just do. The problem with what you're asking is basically that clasically, TVs were built with a better packing of round or otherwise non-square pixels, interleaved halfway between eachother. The image is then sent in 2 frames that update rows 1..3..5..n and 2..4..6..n-1 respectively (i.e. interlaced). If you take that signal and process it back to a matrix form, you need to somehow compensate or otherwise employ an algorithm to create a smoother image, but this ultimately kills small text and other things that rely on very few pixels. There's no good way (by using the video outputs on the console) to put your pandora screen up on a bigger one in decent enough resolution that it's actually an improvement. The S-Video out was obviously designed to fit old tube TVs and as such only push out what they can display.

Ah, I was just about to ask what the essential difference between 'televisions' and 'monitors' was. That's it, then?
 
Last edited by a moderator:
Probably not ideal but I think there are usb external video cards.
 
http://www.desktoplinux.com/news/NS3167589970.html Not cheap but might work sometime in the future ...?
 
search forums for 'sisusb':

http://www.gp32x.de/board/index.php?/topic/46780-usb-2-vga-works-on-linux-plug-play/

http://www.gp32x.de/board/index.php?/topic/45237-new-usb-to-hdmi-adapter/page__st__15
 
Last edited by a moderator:
Back
Top